Attempted to illuminate practical limitations on the Rasch model by focusing on the recovery of the density scale through five simulation trials. Results show that when error distributions are insufficient, the results may be ordinal at best, and when error distributions are nonsymmetrical, the positions of items may be biased with respect to the…

Generalizability Theory can be used to assess reliability in the presence of multiple sources and different types of error. It provides a flexible alternative to Classical Theory and can handle estimation of interrater reliability with any number of raters. (SK)

A Monte Carlo study compared the accuracy of different estimates of the standard error of correlations corrected for restriction in range. The procedure suggested by P. Bobko and A. Rieck (1980) generated the most accurate estimates of the standard error. Aspects of accuracy are discussed. (SLD)

Monte Carlo study results show that the runs test yields markedly asymmetrical error rates in the two tails and that neither directional nor nondirectional tests are satisfactory with respect to Type I errors. The test is not recommended for evaluating the independence of errors in time-series regression models. (SLD)

Introduces the Rater Bundle Model, an item response model for repeated ratings of student work. Applies the model to real and simulated data to illustrate the approach, which was motivated by the observation that when repeated ratings occur, the assumption of conditional independence is violated, and current item response models can then…

Derived formulas for the asymptotic standard errors of component loading estimates to cover the cases of principal component analysis for unstandardized and standardized variables with orthogonal and oblique rotations. Used the formulas with a real correlation matrix of 355 subjects who took 12 psychological tests. (SLD)

T. Vacha-Haase (1998) proposed her "reliability generalization" methodology to characterize (a) typical score reliability for a measure across studies, (b) the variability of score reliabilities, and (c) what measurement protocol features predict the variability in score reliabilities across administration. The present article provides…

Findings indicate that high cortisol levels and interfering substances in formula and breast milk could contaminate salivary cortisol measurements in young infants. To insure accurate results, appropriate controls should be taken for salivary cortisol measurements of young infants. (RH)

Two Tukey multiple comparisons and Bonferroni and multivariate approaches are compared for their rates of Type I error and any-pairs power when multisample sphericity was not satisfied and the design was unbalanced. For tests of weighted means and for study conditions investigated, the Bonferroni procedure provides a workable solution. (TJH)

A general delta method is described for computing the standard error (SE) of a chain of linear equations. The general delta method derives the SEs directly from the moments of the score distributions obtained in the equating chain. Computer simulations demonstrate the method. (SLD)

Occupational employment projections for 1990 were conservative. Detailed comparison of projected and actual increases shows that too many occupations were projected to have average growth and more of those expected to have rapid growth were underprojected. (Author)

Illustrates and compares three alternative procedures to adjust significance levels for multiplicity: (1) the traditional Bonferroni technique; (2) a sequential Bonferroni technique; and (3) a sequential approach to control the false discovery rate proposed by Y. Benjamini and Y. Hochberg (1995). Explains advantages of the Benjamini and Hochberg…

Provides a comprehensive and integrated treatment of both conditional absolute standard errors of measurement (SEM) and conditional relative SEMs from the perspective of generalizability theory. Illustrates the approach with examples from commercial standardized tests. Examples support the conclusion that both types of conditional SEMs tend to be…

The findings of a study of 55 elderly adults support the test-retest reliability of the Assessment of Motor and Process Skills, illustrate the utility of alternative methods for examining the reliability of individual subjects' measures, and indicate that not all test-retest differences represent measurement error. (Author/JOW)

Two relatively simple methods for estimating the condition standard error of measurement (SEM) for nonlinearly derived score scales are proposed. Applications indicate that these two procedures produce fairly consistent estimates that tend to peak near the high end of the scale and reach a minimum in the middle of the raw score scale. (SLD)